In certain laparoscopic or endoscopic surgeries, such as the laser enucleation of the prostate, hysterectomy or other procedures, there is a need to extract masses of tissue from a surgical site to outside of the body through a channel formed in an endoscope. That channel is generally known as and will be referred to herein as a working channel.
A morcellation device is one type of instrument frequently used to cut masses of tissue into smaller pieces and to then to extract these smaller pieces through a channel within the morcellator. The morcellator may have (and usually does have) a number of channels whose various uses or functions are described herein.
In the prior art, rotational morcellators, such as disclosed in U.S. Pat. No. 8,998,887 or linear morcellators, such as disclosed in U.S. Pat. No. 8,945,021 are known. One common feature of these morcellation devices is the application of negative pressure through a channel of the morcellator. The negative pressure induced pulls a tissue mass toward an opening located in the distal tip of the morcellator. The negative pressure further assures mechanical contact between the tissue mass and one or more moving blades located in the opening. Rotational or linear blades move inside a working channel of the morcellator and cut the tissue mass into smaller pieces which can then be suctioned out of the body through a channel in the morcellator.
Different tools may be inserted through the endoscope and into a surgical site, such as graspers, suturing devices, lasers, knifes etc. The endoscope itself is inserted into the body through a natural orifice or through an incision site. In a laser enucleation procedure, for example, an ureteroscope is inserted through the urethra into the bladder. A waveguide is then inserted through the scope into the bladder and up to the prostate in order to deliver the laser radiation to cut pieces of the prostate, in the case, for example, of benign prostate hyperplasia. Masses of prostate tissue then fall into the bladder and these masses need to be removed from the patient's body through a working channel of the endoscope. These tissue masses, however, may be too large to fit and move through the working channel of the endoscope unless cut into smaller pieces. Therefore, a morcellation device may then be applied to first cut the tissue mass in the bladder and only then to use a suction channel to extract them from the patient.
The level of vacuum in the working channel of the morcellator, among other parameters, controls the efficacy of the morcellator for pulling tissue masses floating in the bladder into its opening and the level of mechanical contact a tissue mass establishes with the morcellator's moving blades. However, there is a practical limit to the vacuum level which can be created inside the bladder. As a result, often the suction or vacuum forces designed to pull tissue masses toward the opening in the morcellator shaft are insufficient and, further, there may be insufficient mechanical coupling during morcellation between a tissue mass and the moving blades. As a result, expensive time is wasted chasing tissue masses which become separated from the morcellator during the cutting process.
A variety of solutions are suggested in the prior art for dealing with these problems. One set of possible solutions is the implementation of different blade designs and geometries, such as disclosed in US Patent application 2008039880, which discloses a round blade with grooves which are designed to better hold the tissue and keep it in place. Serrated blades along or across a morcellator's opening are disclosed in US Patent application 2015305765, WO16018457, U.S. Pat. No. 9,433,437, or in US patent application no. 2016235469 to provide an improved cutting mechanism.
Also known in the prior art are baskets and snares mechanisms, such as disclosed, for example, in U.S. Pat. No. 8,435,237 or US Patent application no. 2016045214, which are designed to be inserted in a folded position through an endoscope or a morcellator into a surgical site and to collect tissue debris in an extended position distally to the surgical instrument. Snaring and wire-cutting loops are also known and are disclosed, for example, in US Patent application no. 20122289971. The foregoing US patent application discloses an extendable loop wire which is designed to hold a tissue mass in the vicinity of a surgical grasper. Yet, an improved mechanism to collect, hold and cut tissue masses effectively within a surgical site is still desired and needed. It is one aspect of the present invention to provide a morcellation system with improved efficiency to remedy the above shortcomings of the prior art devices.